It is often necessary to repackage flat or curved glass from steel "leanback" glass racks and place the glass sheets into irregularly-shaped wooden crates for shipping. Such wooden crates are often warped and handmade. It is desirable to place such glass sheets into such low cost wooden crates quickly and in a repeatable fashion.
Previous attempts to load such glass sheets into such wooden crates employed known box location assumptions but ignored positional irregularities related to the box bottom or floor. One approach that has been used to detect such positional irregularities is to use a sensor to locate the bottom of the shipping crate. The U.S. Patent to Pearson, U.S. Pat. No. 5,387,068 discloses a method, a system and an end effector for use therein to provide selective vehicle compliance which allows for packaging sheet material such as glass sheets into irregularly-shaped shipping crates.
However, none of the prior art noted above deal with a robotic system for repackaging glass panels into irregularity-shaped crates wherein the glass panels are presented with large side-edge to side-edge positional variations. Glass panels must be loaded into shipping crates with no side-to-side variation (i.e., the pack of glass panels should appear as a "block of ice"). Any variation in the side-to-side glass edge repeatability leads to shifts in glass during shipment. These shifts in glass result in "etch" marks, scratches, and occasional breaks.